In the Japanese version's commentary with the game's composer Masaharu Iwata, he stated that the "Decisive Battle" felt out of step with the game's historical period. He felt it was more like "a muscle-bound action hero wielding a gatling gun in one hand", instead of wielding sword and sorcery, and apologized if it sounded a little phoned in, adding "I'd do it differently now".
Contributed by ProtoSnake